1. Field of the Invention
The present invention relates to the construction of a bulb socket used in automobiles and the like.
2. Description of the Related Art
Conventional bulb sockets used for lighting of automobiles and the like are constructed as follows: a water-proof plug is fit to the bottom of the socket, and the plug has a center hole at its center within which the hole a plurality of annular projecting portions are formed, and through which a wire is passed and held. A core of the wire is soldered to a tip contact electrode provided at the center of a disk with a substantially smaller diameter than the bore of the socket. A coil spring is inserted between the disk and the water-proof plug, thereby the disk having the tip contact electrode is held elastically towards a bulb insertion portion of the socket.
Since the conventional bulb socket is constructed as above-described, the following assembly procedure must be observed; the wire having an end portion of the core thereof exposed therefrom is passed through the center hole of the water-proof plug, the coil spring is disposed around the wire, and the core at the end is soldered to the mated side of the tip contact electrode at the center of the disk. Then, the water-proof plug through which the wire is passed is fit into the bottom of the socket, and the wire is laid out of the water-proof plug. A retaining protrusion provided on the disk is engaged with an engaging recess portion of the socket while the disk compresses the coil spring. Thus, the assembly of the bulb socket is completed.
As to inserting the bulb into the socket and fixing it, the bulb is rotated with inserting the engaging protrusion provided on the side electrode contact of the bulb into an L-shaped retaining groove formed inside of the socket body, whereby the tip contact electrode of the bulb is brought into contact with the tip contact electrode of the disk as the former presses down the disk.
As will be clearly understood from the foregoing description of the related art, the assembly of the conventional bulb socket is extremely troublesome for the following reasons. After the wire is passed through the center hole of the water-proof plug, the coil spring is disposed around the wire, and the core is soldered to the tip contact electrode of the disk. The retaining protrusion is engaged with the engaging recess portion of the socket body while the disk compresses the coil spring.